Natural siphon autographic raingauge

Llansadwrn (Anglesey) Weather

Observations from the observer's spreadsheet

NOVEMBER 2025

 Logo: Llansadwrn Weather - Melin Llynnon, Ynys Môn.

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CLIMATOLOGICAL OBSERVATIONS AT LLANSADWRN, ANGLESEY, FOR NOVEMBER 2025
<----09 GMT----> <-----------Air temperature--------> <---Soil temp---> <---Earth temp---> <--State of Grd.--> Rain Sol <---Weather----> Press Pptn Fr. Pch
DD N dd ff V ww Temp Dpt RH Max Min Mean Gmin 5cm 10cm 20cm 30cm 50cm 100cm E C Gr SS mm MJ/m2 S L H T G F mb W hrs hrs evap
1 7 W 2 7 25 9.6 7.7 88 11.8 9.0 10.4 7.5 10.1 10.5 11.0 11.3 11.8 12.5 1 2 3 0 9.3 4.36 4 995 7 0.0 0.8
2 5 SW 2 7 01 7.0 5.3 89 12.9 3.8 8.4 1.2 7.8 8.7 10.0 10.9 11.8 12.6 1 2 3 0 16.0 8.05 1005 10 0.0 0.6
3 8 SW 5 5 58 12.9 11.7 92 13.9 7.0 10.5 5.9 13.0 11.4 10.3 11.2 11.5 12.5 1 3 3 0 10.5 1.48 1004 16 0.0 0.4
4 8 SW 6 4 51 13.7 13.3 98 15.2 12.9 14.1 12.3 13.0 12.7 11.7 11.8 12.2 12.5 1 3 3 0 15.6 2.00 1003 9 0.0 0.4
5 8 S 5 5 61 15.1 13.1 88 16.6 12.9 14.8 12.4 13.4 13.8 12.5 12.5 12.5 12.5 1 3 3 0 1.3 1.55 1000 2 0.0 1.2
6 6 SE 1 7 02 15.1 12.2 83 16.6 13.3 15.0 9.2 13.2 12.8 12.6 12.6 12.6 12.6 1 2 3 0 0.3 2.76 1003 3 0.0 0.6
7 6 S 3 7 25 13.4 9.5 97 14.7 10.7 12.7 6.7 11.7 11.8 12.1 12.5 12.5 12.5 1 2 3 0 1.3 2.01 1002 5 0.0 0.8
8 1 00 0 6 05 8.9 7.8 93 13.4 8.4 10.9 5.5 10.5 11.4 11.9 12.2 12.5 12.8 1 2 3 0 0.4 5.64 1011 2 0.0 1.2
9 8 S 5 6 25 12.3 9.7 84 13.5 8.9 11.2 7.7 11.1 11.2 11.7 12.1 12.5 12.9 1 2 3 0 5.8 2.68 1009 10 0.0 0.3
10 6 S 2 6 05 10.5 88.0 89 12.7 9.7 11.2 7.8 10.4 10.8 11.5 12.1 12.5 12.8 1 2 3 0 10.8 2.58 1001 14 0.0 0.7
11 8 S 5 5 80 12.7 11.3 91 14.9 7.4 11.2 4.7 10.8 10.5 10.8 11.2 12.3 12.5 1 3 3 0 5.4 3.04 996 9 0.0 0.8
12 8 W 1 7 05 11.9 10.7 92 13.3 10.8 12.1 8.0 11.0 11.2 11.2 12.1 12.3 12.8 1 2 3 0 26.2 1.93 1000 15 0.0 0.2
13 6 SW 4 5 01 12.3 10.7 90 14.9 11.5 13.2 9.7 11.2 11.3 11.6 11.9 12.2 12.5 1 2 3 0 1.6 5.57 1003 7 0.0 0.4
14 8 E 5 5 51 8.4 6.9 90 8.4 8.3 8.4 4.8 10.0 10.7 11.4 11.8 12.1 12.4 1 3 3 0 25.6 0.97 1005 22 0.0 0.4
15 7 E 3 7 15 8.2 6.6 90 11.0 6.4 8.7 5.8 8.6 9.2 10.0 10.9 11.9 12.5 1 2 3 0 0.1 4.58 1010 0 0.0 0.3
16 8 NE 2 7 06 8.2 6.6 90 9.3 7.8 8.6 6.7 9.0 9.7 10.0 10.7 11.6 12.2 1 2 3 0 0.0 3.47 1016 0 0.0 1.5
17 5 NE 2 7 01 8.0 5.6 85 9.2 4.7 7.0 3.1 6.1 7.7 9.2 10.2 11.3 12.2 1 0 0 0 1.2 5.19 1027 3 0.0 1.0
18 8 SW 2 5 80 6.0 4.8 92 8.6 2.9 5.8 -0.6 6.7 7.5 8.2 9.9 10.8 12.0 1 3 3 0 6.3 3.00 3 1018 13 0.0 0.9
19 7 N 4 7 01 4.0 0.1 76 6.1 3.2 4.7 1.5 5.2 6.5 8.2 9.3 10.6 11.8 1 0 0 0 0.3 4.26 3 1017 1 0.0 2.1
20 2 N 3 7 03 3.6 -1.4 70 7.1 2.1 4.6 -1.4 3.3 5.0 7.5 8.7 10.0 11.8 1 0 9 0 0.0 4.24 1018 0 0.0 1.8
21 2 SE 1 7 01 0.6 -1.1 88 8.4 -0.1 4.2 -3.6 2.8 4.4 6.3 7.8 9.8 11.3 1 0 7 0 20.2 4.83 1028 7 0.0 1.8
22 7 NW 1 6 01 6.1 5.0 93 10.1 0.6 5.4 -1.2 6.3 6.1 6.9 8.0 9.0 11.1 1 2 4 0 8.0 4.23 1014 6 0.0 0.3
23 8 W 4 6 58 6.5 4.7 88 8.8 4.8 6.8 1.3 6.7 7.7 7.2 8.3 9.2 10.7 1 3 3 0 4.0 2.79 997 5 0.0 0.7
24 7 N 4 6 02 7.4 5.5 88 9.3 3.8 6.6 0.8 1.0 6.4 10.8 7.1 8.2 10.3 1 1 2 3 0.1 2.95 995 1 0.0 2.4
25 1 N 2 8 02 4.8 1.1 77 8.9 4.3 6.6 0.6 4.3 5.7 6.8 8.1 9.2 10.8 1 0 1 0 0.0 4.40 1018 1 0.0 1.0
26 8 S 5 6 03 7.4 4.2 80 11.9 1.7 6.8 -2.0 5.1 5.3 6.0 7.2 9.0 10.2 1 0 0 0 0.8 2.41 1019 5 0.0 1.0
27 8 SW 4 6 81 11.8 10.8 94 12.8 7.4 10.1 6.0 10.5 9.5 8.5 8.5 9.0 10.2 1 3 3 0 2.9 0.91 1008 5 0.0 1.0
28 8 SW 6 6 16 10.0 7.1 82 10.9 9.7 10.3 6.3 8.5 8.8 8.3 8.9 9.5 10.1 1 0 0 0 6.8 1.94 T 1004 5 0.0 0.8
29 3 00 0 6 03 4.2 3.1 93 6.6 4.0 5.3 0.8 5.8 6.7 7.2 8.3 9.2 10.2 1 2 3 0 9.8 1.32 1000 12 0.0 0.4
30 2 SW 2 6 05 2.9 1.9 93 11.4 2.3 6.9 -0.7 4.5 5.7 6.5 7.8 9.1 10.1 1 2 4 0 31.2 3.18 3 993 15 0.0 0.8
N 76 %
Means----> 8.8 9.4 88 11.4 6.7 9.1 4.2 8.4 9.0 9.6 10.2 11.0 11.8 3.28 1007
Totals-----> 221.8 98.31 0 0 4 1 0 0 210 0.0 26.6
MEANS AND AVERAGES AT LLANSADWRN, ANGLESEY FOR NOVEMBER 2025
Differences from 2015-2024 average* & from 1991-2020 average**.
Air temperature (C) * ** Weather (No. days occurrence) * Wind direction (days) Rainfall (mm) * **
Mean maximum 11.4 0.5 1.0 Sleet/ snow falling 0 -0.9 N 4 Total 221.8 156 167 %
Mean minimum 6.7 0.8 1.2 Snow lying (at 09 GMT) 0 0.0 NE 2 Largest fall 31.2
Mean (max+min)/2 9.1 0.7 1.1 Hail <5 mm 4 -0.3 E 2
Highest maximum 16.6 0.8 Hail >=5 mm 0 {All types} SE 2 Evaporation (mm)
Lowest maximum 6.1 -0.2 Thunder heard 1 0.6 S 6 Lysimeter PE 20.0
Highest minimum 13.3 1.9 Gales 0 n.a. SW 8 Monthly total PWB 201.8
Lowest minimum -0.1 -0.8 Fog (at 09 GMT) 0 n.a. W 3 PWS 210.8
No. days <0.0C 1 0.8 Rainfall (No. days occurrence) NW 1 PWD -0.4
Grass minimum mean 4.2 1.2 No pptn 0.0 mm 3 -0.8 Calm 2 AWS ET 19.0
Lowest minimum -3.6 -0.3 Dry < 0.2 mm 5 -2.8 Piche (ml) 26.6
No. days <0.0C 6 -1.4 Rain >= 0.2 mm 25 2.5 Check days 30
Earth temperature 30cm 10.2 0.6 Wet >= 1.0 mm 21 3.7 This month 30
>= 5.0 mm 15 5.8
Nov_temp.gif Nov_rain.gif Nov_msl.gif Nov_soil.gif Nov_sol.gif Nov_rh.gif Nov_wind.gif Nov_pe.gif

Note: Unusual peaks seen on the PE graph are due to recent rainfalls or unmelted snow having not yet percolated through the soil. This method is not good for daily measurements, but good results are obtained over 3 days (allowing time for percolation) and on a monthly basis. The lysimeter also measures dew and depositions of frost, and is a better raingauge than one with a rim at 30 cm high. In winter, when evaporation from the ground is low, negative values are sometimes seen and indicate an accumulation of dew and frost, and more rain than measured by a standard raingauge. In summer, when evaporation is high and rainfall less, the lysimeter still measures dew and more rain than the standard gauge, but the effect is less noticeable. The daily graph is show here for it's interest and you can read more about this 'classic' method of measuring evaporation here

.

KEY: OBSERVATIONS AT 09 GMT

  DD date; N cloud (oktas, 9=obscured); DD wind direction (8 sectors, 00=calm); ff wind speed (Beaufort scale);
  V visibility (0 dense fog, 1 thick fog, 2 fog, 3 moderate fog, 4 very poor, 5 poor, 6 moderate, 7 good, 8 very good);
  WW present weather SYNOP code (eg. 01 cloud decreasing, 02 sky not changing, 03 cloud increasing, 04 smoke haze, 05 haze)
  Temperatures (degC); Temp dry bulb temperature; Dpt dewpoint; RH relative humidity (%); soil temperatures are under bare
  soil and earth under grass; SS snow depth (cm); Press air pressure, aneroid (mb). For state of the ground E, concrete C,
  and grass Gr codes consult the page on 'Recording Atmospheric Depositions on Grass'. =0 bare soil very dry and cracked;
  +2 local flash flooding.
 

24 hour observations...


  Max maximum temperature (degC) beginning 09GMT; Min minimum temperature ending 09GMT;
  Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning 09GMT;
  Rain rainfall beginning 09GMT (mm); Pptn  W hrs number of hours with precipitation 09-09GMT; trace <0.05 mm; tr trace of rain; tr dw trace of dew;
  tr fr trace of frost; Fr. hrs hours of frost (09-09GMT).
  Sol MJ/m2 Global Solar Radiation (MJ per m2) 00-00 GMT. 

Monthly observations...

  PE Potential evapotranspiration, PWB Potential water balance, PWS Potential water surplus, PWD Potential water deficit.

Weather: days with...

  s slight or S heavy snow/sleet falling; L >=50% snow cover at 09GMT; H categories of hail: 1 ice crystals, 2 snow grains,
  3 snow pellets, 4 ice pellets, 5 hail 5-9 mm, 6 hail 10-19 mm; up unidentified precipitation;
  t slight or T heavy thunder heard; G gale; Fog any hour 1, 09 GMT 9. Gales (Beaufort land scale) refer to the area.

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